1. Field of the Invention
A band for reattachment of the retina of an eye by means of scleral buckling.
2. Prior Art
Retinal detachment is a pathological disorder which occurs when there is a separation of two adjacent layers (the neurosensory retina and the retinal pigment epithileum) within the eye which normally remain in apposition. This disorder, if not detected early and treated, results in partial or total blindness. Retinal detachment may be preceded by a visual perception of a shower of "sparks" or "lightening flashes" and may be accompanied by a shower of "floaters". Floaters are perceived as spots before one or both eyes.
In a healthy individual, the vitreous choroid functions to give shape to the eye, aids in the transmission of light from the lens to the retina and may provide support to maintain the retina against the underlying retinal pigment epithelial layer. When an individual ages, the vitreous choroid may become liquefied at the retina-vitreal interface with consequent pulling away from the retina. This can result in a tear or retinal break. Continued traction upon the retinal break can result in the passage of vitreous fluid through the retinal break and under the retina resulting in retinal detachment.
Methods for treating retinal detachment are known in the prior art. Such methods include the removal of the vitreous gel from the eye and/or the injection of a gas into the vitreal chamber (pneumatic retinopexy) to seal a retinal detachment or tear in the upper region of the eye where the gas is used to apply pressure against the retina. If detachment has occurred, the pressure of the gas can hold the retina against the subjacent or underlying tissue and facilitate a reattachment of the retina to the subjacent tissue. Once the adjacent tissue layers are brought into juxtaposition, various treatment modalities may be used to create an adhesion between the retinal tear and the underlying tissue to assist in a more permanent attachment process which progresses with time. Such modalities include laser photocoagulation and or cryotherapy.
A procedure known as scleral bucking is also used to repair a detached retina. In this procedure, an elastic, compressive band is placed around the eye. A sponge or wedge is placed between the band and the portion of the sclera overlying the region of detachment. Tension on the band circumferentially compresses the sclera and deforms the eye, increasing the pressure of the vitreous humor and bringing the choroidal retinal pigment epithelial layer underlying the retina into juxtaposition. The band is held in an encircling position around the eye by means of a clasp affixed to the band to join opposing ends. In addition, a scleral buckling band may further include an inflatable balloon which may be positioned to overlie the area of detachment. Components of a scleral banding device minimally include a solid silicone band, a silicone member, preferably a sponge, and a clip for attaching the ends of band around the eye. Such scleral buckling band components are commercially available from: Mira, Inc., 87 Rumford Avenue, Waltham, Mass. 02154 and Stortz Instruments, St. Louis, Mo.
A problem associated with such prior art scleral buckling devices is that the (differentially compressive) silicone member may slip out from underneath the band during use. Thus, the silicone band and silicone differentially compressive member must both be sutured to the sclera of the eye to prevent the post-operative displacement of the compressive member overlying the retinal tear so that treatment is successful. In addition, the prior art scleral buckling devices present a more or less irregular, discontinuous surface to the sclera of the eye which, when the eye is compressed, may lead to undue and unwanted pressure applied to non-target areas of the sclera. It would, therefore, be desirable to provide a scleral buckling device wherein the differentially compressive portion and elastomeric band are unitary in construction. It would further be desirable to have the scleral-contacting surface of the band present minimum discontinuities or pressure points on non-target tissues of the eye.